window.onload=function(){
    oUl=document.getElementById("nav");
    lis=oUl.getElementsByTagName("li");

    for (var i = 0; i < lis.length; i++) {
        lis[i].onclick=function(){

            oUl.className="nav  "+this.className;
            console.log(oUl.className);
            var score=this.getElementsByTagName("a")[0].title;
            alert("评分是："+score);
            location.href="index.html";
        }
    }
}